expression, godan verb (-u)
speak clearly; speak distinctly
Focuses on the clarity of articulation or expression, not on bluntness.
電話では、はっきり言ってください。
Please speak clearly on the phone.
expression, godan verb (-u)
be frank; put it bluntly; get to the point
Used when stating an opinion or fact directly, without softening. Often implies a degree of bluntness.
はっきり言って、その計画は無理だと思う。
To be frank, I think that plan is impossible.